Prof. Eric Laithwaite Inertial Propulsion & angular momentum of gyroscope

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Rafael Ti
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Prof. Eric Laithwaite Inertial Propulsion & angular mome

Post by Rafael Ti »

Hi all
I couldn't resist not posting this video. From 10:00 minute he shows how the angular momentum of spinning gyroscope
suddenly disappears when the weight is taken off. Good video about interesting man of science.
https://www.youtube.com/watch?v=1eQp4grGdqY
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re: Prof. Eric Laithwaite Inertial Propulsion & angular

Post by ME »

Marchello E.
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re: Prof. Eric Laithwaite Inertial Propulsion & angular

Post by Rafael Ti »

Thx... and what happens when we somehow disturb the mass in spinning gyroscope? What if we join two gyroscopes
spinning in opposite directions on one axle (to achieve the balance) and then interfere in to mass or length of arm
at some point of rotation? We fly away or at least move away :)
Here is how the simplest "UFO" works :)
https://www.youtube.com/watch?v=bXDXcXFhMnw
The guy called it the Evoligram.
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Post by ME »

Gyroscopes are funny things, but they can't fly as they need to be able to react against something... the ground for example.

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I guess you'll like this one: SmartSPIN X2
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Post by Grimer »

ME wrote:Gyroscopes are funny things, but they can't fly as they need to be able to react against something... the ground for example.

...
What about reaction against the aether.

Oh! silly me. The aether doesn't exist does it - or so we are told.

The fact a rotating body can tell whether it is rotating or not relative to the "fixed stars" isn't because it can sense its rotation relative to the stationary surrounding aether (which doesn't exist). It's pure magic.

The fact there's an absolute frame of reference with respect to rotation is brought about by the incantations of free masons no doubt.
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Post by jim_mich »

Hey, don't let Ralph read that... he doesn't know sarcasm even if it hits him between the eyes.

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re: Prof. Eric Laithwaite Inertial Propulsion & angular

Post by Wubbly »

From 10:00 minute he shows how the angular momentum of spinning gyroscope
suddenly disappears when the weight is taken off. Good video about interesting man of science.
https://www.youtube.com/watch?v=1eQp4grGdqY
Erik Laithwaite clearly misunderstood gyroscopes. The angular momentum does not disappear. The spinning gyroscope still has a huge amount of angular momentum due to its spin. He simply reduced the total system angular momentum by a very small amount by eliminating a torque on the system.
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Post by Grimer »

Eric Laithwaite intuitively recognised the importance of the 3rd derivative, the key to harnessing the gravitational wind.
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re: Prof. Eric Laithwaite Inertial Propulsion & angular

Post by ME »

Any circular vector can be split into a horizontal and vertical component, where the vertical component could be something like gravity.
These components are the Sine & Cosine of that circular vector, which have a known Taylor expansion: an infinite degree of polynomials...(or if you like: the sum of infinite derivatives)


Grimer a serious question, perhaps you know (as I don't), what happens to a gyroscope doing figure-eights (for example) around the moon and earth? Will its orientation be based on the nearest mass or would it be able to keep some absolute reference point?
Marchello E.
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re: Prof. Eric Laithwaite Inertial Propulsion & angular

Post by Grimer »

ME wrote:Any circular vector can be split into a horizontal and vertical component, where the vertical component could be something like gravity.
These components are the Sine & Cosine of that circular vector, which have a known Taylor expansion: an infinite degree of polynomials...(or if you like: the sum of infinite derivatives)

Grimer a serious question, perhaps you know (as I don't), what happens to a gyroscope doing figure-eights (for example) around the moon and earth? Will its orientation be based on the nearest mass or would it be able to keep some absolute reference point?
Mmm... Taylor expansions, eh! That takes me back. Mind you, I've never had to use a Taylor expansion in anger. :-)

As regards your serious question, since I presume the gyro would be in a state of free fall I believe it would be sensing the universal frame of reference of the external atmosphere which is holding it together, the frame of reference of the fixed stars in other words.

From the above answer you can correctly infer that I don't believe materials are held together by internal tensions but by external pressures of the appropriate fraction of the aether.

A propos nothing in particular I notice that your home is Holland. If my mother had been my father and her mother had been my grandfather my name wouldn't have been Grimer but van Damme.

But I suppose, nowadays, just because one lives in a country doesn't mean one is a native. You're certainly not an English expatriate since if you were you'd be unlikely to chose ME as your handle. ;-)

Myalgic Encephalomyelitis (M.E.) is a long-term (chronic) fluctuating illness that causes symptoms affecting many body systems, more commonly the nervous and immune systems. Defined by the World Health Organisation as neurological, M.E. affects an estimated 250,000 people in the UK, and around 17 million people worldwide.

Edit: Of course if I'd bothered to do my research I would have seen that the M stood for Marchello which has to be Italian. You should have used that. It sounds so musical - just like my Federici grandchildren's names.
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re: Prof. Eric Laithwaite Inertial Propulsion & angular

Post by ME »

ME again...
yeah well - this name is in any case a bit unfortunate on an English forum, tends to sounds a bit narcissistic (would have spelled this more 'Dutchy' myself by leaving that middle 'sis').
Laziness is a (b***), a short username I mean.
---
Taylor expansion: Perhaps only good for making a complicated impression.
What I meant to say: I don't think the 3rd derivative is anything special on itself other than it means a change in acceleration.

Just for completeness sake:

x[t] = x[0] + v[0]*t + (1/2)*a[0]*t^2 + (1/6)*j[0]*t^3 + (1/24)*s[0]*t^4

Where a=acceleration[m/s^2], j=Jerk[m/s^3], s=Shock[m/s^4]

---
Gyro:
(still a background process)

---
Always nice those what-ifs.
If my father's job offer would have been successful, then I would have been born in New Zealand.

Jean Claude van Damme (real name according to wiki: Jean-Claude Camille François Van Varenberg) is from Belgium... close enough to Holland.

---
Enough of this, let's go back to ME.
I could create a new username, but then I would loose all my greenies; nobody wants to loose them... So to compensate and balance the effects caused by that quick signup, perhaps I should now put more effort in signing all my posts with:

Greetings from The Netherlands,
Marchello E.
Marchello E.
-- May the force lift you up. In case it doesn't, try something else.---
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re: Prof. Eric Laithwaite Inertial Propulsion & angular

Post by ME »

(Re)learned, (re)gained some lost (or never learned and used) knowledge: The gyroscopes orientation is like the Foucault pendulum....
wiki wrote:In order to demonstrate the rotation of the Earth without the complication of the dependence on latitude, Foucault used a gyroscope in an 1852 experiment. The gyroscope's spinning rotor tracks the stars directly. Its axis of rotation is observed to return to its original orientation with respect to the earth after one day whatever the latitude, not being subject to the unbalanced Coriolis forces acting on the pendulum as a result of its geometric asymmetry.
- I thought wrongly the Gyro orientation was relative to the closest mass so there would be at least two needed to determine the direction in general plane flight. Hence my puzzling question about a gyro doing figures eights around the earth and moon. So while that's solved, I now question the usefulness for tracking direction when it rotates whatever degrees per so many hours....
(and submerged again as background process)

Thanks G.

Greetings from The Netherlands,
Marchello E.


---
add: (apparently not submerged enough)
Wiki: Foucault pendulum (about parallel transport and other things)
wiki wrote:From the perspective of an inertial frame moving in tandem with Earth, but not sharing its rotation, the suspension point of the pendulum traces out a circular path during one sidereal day. At the latitude of Paris, a full precession cycle takes 32 hours, so after one sidereal day, when the Earth is back in the same orientation as one sidereal day before, the oscillation plane has turned 90 degrees. If the plane of swing was north-south at the outset, it is east-west one sidereal day later. This implies that there has been exchange of momentum; the Earth and the pendulum bob have exchanged momentum. The Earth is so much more massive than the pendulum bob that the Earth's change of momentum is unnoticeable. Nonetheless, since the pendulum bob's plane of swing has shifted, the conservation laws imply that there must have been exchange.

Rather than tracking the change of momentum, the precession of the oscillation plane can efficiently be described as a case of parallel transport. For that, it can be demonstrated, by composing the infinitesimal rotations, that the precession rate is proportional to the projection of the angular velocity of Earth onto the normal direction to Earth, which implies that the trace of the plane of oscillation will undergo parallel transport. After 24 hours, the difference between initial and final orientations of the trace in the Earth frame is α = −2πsin(φ), which corresponds to the value given by the Gauss–Bonnet theorem. α is also called the holonomy or geometric phase of the pendulum. When analyzing earthbound motions, the Earth frame is not an inertial frame, but rotates about the local vertical at an effective rate of 2π sin(φ) radians per day. A simple method employing parallel transport within cones tangent to the Earth's surface can be used to describe the rotation angle of the swing plane of Foucault's pendulum
Marchello E.
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re: Prof. Eric Laithwaite Inertial Propulsion & angular

Post by Rafael Ti »

Gyroscopes in the space do still the same job...
https://www.youtube.com/watch?v=kCyMZFwb_O8
and BTW:
A weird behavior of magnets (not) explained by prof. Laithwaite (Imperial College London 1968)
https://www.youtube.com/watch?v=0tJfqMYHaQw
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Post by Grimer »

That Laithwaite stuff is most interesting.

It deserves a greenie.
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re: Prof. Eric Laithwaite Inertial Propulsion & angular

Post by Rafael Ti »

Thank you.
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